The Duomatic hub production started in 1964. This was the time of the german “Wirtschaftswunder”. This was the time with a strong economic growth after world war two. The germans bought the VW Käfer (Volkswagen Beetle) and loved the new freedom. But how to transport a bicycle in the Beetle? This was the point where the Klapprad was invented.

A 20″ bicycle with a foldable mechanism in the middle of the frame. Like today the bowden cable for gear shifting and braking was a constructive challenge. The fabulous solution was the Torpedo Duomatic two gear hub.

A coaster brake without any bowden cable and a fantastic two gear shifting mechanism. The link between the hub and the rider was not as common today a bowden cable. The new link was the chain! By pedaling a little bit backwards the shifting mechanism switches from one gear to the other. While using the coaster brake the hub shifts also from one gear into the other. This makes sense! When you ride in the fast second gear you´ll start accelerating again in the slow first one because of the coaster braking. Perfect!

This invention made it easy to fold the bike without any problems of bowden cables! Why? Because there were none!

The 20″ Klapprad wheels are the reason that nearly all Duomatic hubs came with 28 spoke holes. There were a few hubs sold mainly in the Netherlands and Scandinavia with 36 spoke holes. Because this bicycle country with cold winters recognized the big advantage to use this hub for a maintenance free commuting bike. With this hub there were no disrupted and frozen bowden cables anymore.

After a few miles you are familiar with the shifting behaviour after a brake. Because while braking the hub switches to the next gear. What will happen is quite similar to fixed gear cycling. Your attention goes up and you´ll think forward. The options: Do I use the front brake and stay in the second gear or do I brake with the coaster brake and start accelerating with the first one.

It´s fun!

Options:

– 28 spoke hole version

– 36 spoke hole version (very rare!)

– older versions come with a 10,5mm axel diameter and two flat sides of the axel (Duomatic 102)

– version with common 9,5 mm axel diameter (Duomatic R 2110)

Share this:

Related

I love your site. Sachs two speed hubs are my favorite hubs. I have about 5 of them. I have a few kickbacks and few automatics. I also bought various parts to repair them from a closed bicycle shop in Canada. I have a small bicycle company in New York City. I have actually asked SRAM (the company that now has the Duomatic tooling) to make these hubs again. Perhaps some day they will.

I was just at the local recycling center and found an old bike in the metal bin. It had some cool features like an old drum break on the front wheel and unique frame architecture. When I got it home I discovered it also has a torpedo duomatic from 1966. Pumped up the tires and it rides great. The duomatic is perfect.

I ran a duomatic hub on a modified road frame for about 5 years. The bike was affectionately known as the Torpedo. I found the hub in an old Raleigh 20 bike (a New Zealand produced version). Among its may benefits is the ability to commute almost completely no-handed, braking and changing gear with hands shoved firmly in pockets – great for those cold mornings!

Moulton have anounced a Limited Edition “Moulton50” to celebrate 50 years of Moulton bicycles – seems to be based on the TSR series. It used the Duomatic, in combination with a heel-operated 2-speed “Speed Drive” chainwheel to give a total of 4 gears (39-52-64-86″). Looks nice – here’s the link: http://www.moultonbicycles.co.uk/models/Moulton50.html

Given that the Duomatic was installed on so many 20″ German klapprads with 28 spoke (28 hole) wheels, what is the availability today of used 28 hole Duomatics in Europe? I’m in the US.
My bike is identical to the pretty green machine pictured above. http://www.flickr.com/photos/39389118@N07/sets/72157621474584178/ Unfortunately, it is a single-speed Sachs ET. If anyone could direct me to a parts/spares vendor who might have a used 28 hole Duomatic, I would appreciate the referral. johnfmccann(at)yahoo(dot)com

[…] stand, on an protoype of the Pashley-built TSR2. The SC2 is Sturmey’s remake of the Fichtel & Sachs Torpedo Duomatic, a two-speed hub with kick-back gear change and coaster brake. These hubs have something of a cult […]

[…] So in doing some research into my options I found that Sturmey-Archer re-released last month an old duomatic design called their S2C hub. This will allow two different speeds and a coaster brake, so ideal […]